by Queen Mary, University of London

Credit: CC0 Public Domain

Smoking in pregnancy can harm developing babies, especially their growth. Current guidelines recommend that pregnant smokers who find quitting difficult should be provided with nicotine replacements products, and stop-smoking services usually recommend nicotine patches.

This research, published in Health Technology Assessment, suggests that pregnant women should also consider e-cigarettes.

The study included 1,140 pregnant women who were trying to stop smoking, who were divided into two groups. Half of the women received e-cigarettes; the other half received nicotine patches. Both approaches were equally safe. The only meaningful difference was that fewer women in the e-cigarette group had children with low birthweight (weighing less than 2,500 grams).

The researchers say this is most likely because e-cigarettes were more effective in reducing the use of conventional cigarettes. Low birthweight has been linked with poor health later in life.

At the end of their pregnancy, women reported whether they had quit. However, some women had quit smoking using a product they were not assigned, mostly women given patches, who stopped with the help of e-cigarettes they had procured for themselves.

When the researchers looked at successful quitters who only used the treatment they were allocated, they found that almost twice as many women had quit with e-cigarettes as with nicotine patches.

The researchers looked at safety outcomes, including low birthweight, baby intensive care admissions, miscarriage, stillbirth, and premature birth.

It is not clear whether nicotine is harmful to developing babies. National Institute of Health and Care Excellence (NICE) states that most health problems are caused by toxins other than nicotine in cigarettes, and therefore recommends that nicotine replacement therapy (such as nicotine patches, gum and mouth spray) be considered alongside behavioral support. However, most pregnant women still struggle to quit.

E-cigarettes can be seen as a form of nicotine replacement therapy, but they have an advantage over nicotine gum and patches in allowing smokers to select strength and flavors they like, and make the transition to stopping smoking easier. This is most likely why e-cigarettes have been shown more effective than the traditional nicotine replacement therapy in people who are not pregnant.

Peter Hajek, Director of Health and Lifestyle Research Unit, Wolfson Institute of Population Health, Queen Mary University of London, said, "E-cigarettes seem more effective than nicotine patches in helping pregnant women to quit smoking and because of this, they seem to also lead to better pregnancy outcomes. The evidence-based advice to smokers already includes, among other options, a recommendation to switch from smoking to e-cigarettes. Such a recommendation can now be extended to smokers who are pregnant as well."

More information: Christopher Griffiths, Helping pregnant smokers quit: A multi-centre randomised controlled trial of electronic cigarette versus nicotine replacement therapy, Health Technology Assessment (2023). DOI: 10.3310/AGTH6901. www.journalslibrary.nihr.ac.uk/hta/AGTH6901/

Provided by Queen Mary, University of London